8. Cylindrical turning and facing of hollow cylindrical parts

Hollow cylindrical parts can be machined with the part held in a
chuck or between centres. The use of counter-supports (steady rest) depends on
the length of the part, the diameter to be machined and the weight of the part.
It is always to be considered an additional support. The cutting is done on the
external or internal surface and end face of the part.

- When chucking thin-walled parts, the chucking pressure must be
selected so as to avoid any deformation of the part. For this purpose, clamping
bushes as per Fig. 25 may be used.

Figure 25 Clamping in clamping bushes

1 clamping bush

- If a tailstock is used as counter-support with a centre
smaller than the bore of the part, thrust pads as per Fig. 26 are to be used.

Figure 26 Counter-supporting by means
of thrust pads

1 thrust pad

- Hollow parts warm up more quickly than solid material during
machining. This fact is to be considered when choosing the cutting values and in
dimensional inspection.

What kinds of counter-supports do you
know?__________________________________________________________________________________________________________________________________________